Sunday, December 20, 2009

'Living Walls' plaster over an 'EcoNest' -- Working with Lime

Alright, this had been a big job, and hence, haven't written in a while. But finally finished and what a good one it has been! Especially for those of you interested in the super flat and super refined earth plaster style. Good to practice.

The structure is a heavy timberframe with a mixture of traditional european and japanese joinery and infilled Light Clay-Straw. It was designed by Paula LaPorte and the construction was led by her husband, Robert Laporte, of EcoNest. My mom was at the straw-clay workshop for this structure, where I got introduced to the project from early on. Little did I know, six months later, when the walls were thoroughly dry, I would be on a team of four to plaster the whole thing.

For this project, I joined the crew of Living Walls, a Portland-based earth plaster company, led by Joshua Klyber. We did a lime plaster system on the outside and earth plaster with aliz on the interior. And we had a lot of fun! This post will focus on the lime plaster portion and my next will cover the earth plaster work. Enjoy!

The site and our mortar mixer set-up.

The Light Straw-Clay walls to be covered.

Base coat of lime goes up

Greg works it!

Comin' around the corner!

base and finish coat shown clearly here

Joshua is so silly sometimes!

Pigmented lime wash

the fun part!

cleaning up the stonework with muriatic acid

classic Econest!

This finish is at minimum a seven-pass system. First, we prime or lathe all windows edges, corners and other expanses of wood. Then we apply the rough base coat of lime plaster which has a lot of gravel. Next we press the plaster with a wood trowel to compact the lime as it dries. Then we score the surface with a small rake or scarifier. Then we come around again with a finish coat, no gravel in it this time. We follow again with a hard-packing motion with a wood trowel. Then we brush all the loose sand from the surface. Finally we apply a lime wash to give the surface color, actually two coats. So in all, we have come around to every square inch of this exterior wall surface nine times. Labor intense, no joke!